This invention is related to compositions and methods for forming a thin membrane on a patch of human or animal skin for protecting the skin area or for applying therapeutic agents through the skin area.
The related prior art in this area is the so-called percutaneous delivery systems for pharmaceutically active substances (“PAS”). For example, U.S. Pat. No. 6,211,250 B1 describes a percutaneous delivery system which is a gel that contains 0.001-50% hydrophilic polymers (such as hydroxypropyl cellulose) and 0.001-50% hydrophobic polymers (such as acrylate/octylpropenamide copolymer). The gel can be applied to skin to form a film-like structure. This kind of percutaneous delivery system, though more resistant to accidental removal than traditional creams, does not form a solid membrane, and thus can still be rubbed off accidentally, preventing long-term and consistent delivery. The present inventions are compositions and methods for forming a skin membrane for the purposes of protecting the skin and/or administering PAS to or through the skin.